Column of an office chair

ABSTRACT

A releasable lock of a tube telescope, variable as to its length, as a column of an office chair, which comprises a cone, and a column tube movable as to its height and having a longitudinal slot at its free lower end. Tongues are supported by the column tube and the cone is pressed in the locking position against the inner face of the tongues. The latter carry a nose member pointing towards the cone, whereby the line of the convex surface of the cone converges in the direction towards a seat of the chair.

United States Patent Spieth et al.

l l l l COLUMN OF AN OFFICE CHAIR Inventors: Albert Spieth, Bziumrente l5, Oberesslingen; Rudolf Spieth, Haus l4, Esslingemoberhol. both of Germany Filed: June 15, 1970 Appl. No.: 45,950

U.S. Cl ..248/4I2, 287/58 CT Int. Cl ..Fl6m 11/00 Field of Search .248/336, 337, 412;

References Cited UNITED STATES PATENTS Morseth ..2s7 5s CT Irish et a] ..287/58 Cl Apr. 17, 1973 FOREIGN PATENTS OR APPLICATIONS [10,458 1 [H965 Great Britain ..248/3 l2 Primary ExamincrWilliam H. Schultz Att0rney-Ernest G. Montague 5 7 ABSTRACT 3 Claims, 3 Drawing Figures COLUMN OF AN OFFICE CHAIR The present invention relates to a column of an office chair, in general, and to a releasable lock of a tubular telescope member which is variable in length and used as a column of an office chair. A spring means comprising a cylinder and piston with a piston rod is provided on the inside, so that a cone of the lock is pressed in locking position against the inner face of tongues of the column tube which is movable with respect to its height and has a longitudinal slot at the free lower end thereof, in particular.

It is one object of the present invention to provide a column for an office chair which includes tongues which carry nose members pointing towards a cone. The pressure zone of the lock is annularly designed, so that instead of punctually limited pressure points, pressure points depending upon the length of the periphery of the movable column tube are provided, which brings about an advantage over the known structures.

With this and other objects in view, which will become apparent in the following detailed description, thepresent invention, which is disclosed by example only, will be clearly understood in connection with the accompanying drawing, in which:

FIG. 1 is an axial section of the column of an office chair; I

I FIG. 2 is an axial section ofa second embodiment of a column of an office chair and;

FIG. 3 is a axial section partly broken away showing another embodiment;

Referring now to the drawing, and in particular to FIG. 1, which indicates an axial section of the column, the main parts comprise an outer column tube 2a, a setting tube 4lhaving preferably integrally a conical ring 3, a gas spring 5 and 6, a threaded closing cap 7 permitting the replacement of the gas spring 5 and 6 and a setting lever 8 for releasing the lock. The outer column tube 20, 2b and 2c is carried by the leg portions 16. The lock permits one to adjust the seat of the chair as to its height. The conical ring 3, the setting tube 4 and the setting lever 8 are spring-biased (not shown).

The cone can be secured on the setting tube 4 which is guided by the cylinder 5. In the embodiment shown by example in FIG. 1, nose projections 20 are impressed into tongue portions 2b formed by longitudinal The embodiment disclosed in FIGS. 2 is substantially of the setting tube 4 mounted in the column tube 2'. Further the upper end of the structure has an eye formation 3b forming an inwardly directed semi-circular cross-section and the swinging setting lever 4a carries a sliding tube 5' rollably contacting the eye formation 3b, and which sliding tube 5' is slightly shorter than the inner diameter of the column tube. In addition, this sliding tube 5 is frictionally held on the end of the lever 4a, the latter being pivotally mounted on the setting tube at point 4a.

Referring now again to the drawing, and in particular to FIG. 3, which shows merely as a variation of the structure disclosed in FIG. I, that the annular groove formed be) means of the nose members in the tongues is filled up y an adhesive brake layer rmg consisting substantially of elastic material of organic origin.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense.

We claim:

1. A releasable lock of a tube telescope, variable as to its length, as a column of an office chair, comprising a setting tube having a cone,

a column,

a column tube coaxially disposed relative to said setting tube and said column movable as to its height relative to said column and having longitudinal slits at its free lower end forming tongue portions, and clampingly lockingly and releasably cooperating with said column,

said tongue portions formed with nose projections cooperating with and pointing towards said cone,

said cone converging in an upward direction towards a seat of the chair,

a setting lever pivotally connected to said column tube for up and down swinging,

a sliding tube inside said column tube in which an end of said setting lever is frictionally mounted,

and an eye formation operatively secured to said setting tube and in which said sliding tube is rollably disposed so as to disengage said cone from operatively pressing lockingly against said tongue portions when said setting lever is swung.

2. The releasable lock, as set forth in claim 1,

said nose projection is impressed in said tongue portions.

3. The releasable lock, as set forth in claim 1,

wherein I said eye formation is annular in shape having an inwardly directed substantially semi-circular cross section. I 

1. A releasable lock of a tube telescope, variable as to its length, as a column of an office chair, comprising a setting tube having a cone, a column, a column tube coaxially disposed relative to said setting tube and said column movable as to its height relative to said column and having longitudinal slits at its free lower end forming tongue portions, and clampingly lockingly and releasably cooperating with said column, said tongue portions formed with nose projections cooperating with and pointing towards said cone, said cone converging in an upward direction towards a seat of the chair, a setting lever pivotally connected to said column tube for up and down swinging, a sliding tube inside said column tube in which an end of said setting lever is frictionally mounted, and an eye formation operatively secured to said setting tube and in which said sliding tube is rollably disposed so as to disengage said cone from operatively pressing lockingly against said tongue portions when said setting lever is swung.
 2. The releasable lock, as set forth in claim 1, said nose projection is impressed in said tongue portions.
 3. The releasable lock, as set forth in claim 1, wherein said eye formation is annular in shape having an inwardly directed substantially semi-circular cross-section. 